An opto-magnetic disk has been known as the large capacity recording medium permitting data re-writing. The data writing, reading and erasure to and from the opto-magnetic disk are usually performed with the use of a laser beam emitted by a laser diode. Heretofore, at the time of data writing or erasure, the laser diode remains energized during the periods other than the periods during which the laser beam irradiation is actually required, with the result that the life of the laser diode is short and the demanded guarantee time cannot be satisfied.
The tracks on the opto-magnetic disk are each divided into a plurality of sections, each of which is provided with a gap region for absorbing temporary errors, with the data being recorded in synchronism with each sector as one unit to effect data management or control on the sector basis.
With the opto-magnetic disk apparatus in which the opto-magnetic disk is employed as the recording medium and the data are recorded and/or reproduced by a laser diode, problems are presented as to the life of the laser diode and the reduction in the effective disk capacity, with the gap region provided in each track sector on the opto-magnetic disk representing an ineffective recording region.
It is therefore an object of the present invention to provide an optical disk recording/reproducing apparatus enabling the life of the laser diode to be lengthened and the disk capacity to be effectively utilized.